Why Campbell Crashed
Published in The Daily Express January 1967, Written by: David Benson

Donald Campbell's last, fatal run on Lake Coniston on January 4 was definitely not a "do or die" attempt. A technological analysis of the two runs made that morning by Bluebird reveals that the boat was in fact going slower when it took off than the average speed it maintained in the first run.

The analysis was done at the instigation of the Daily Express and in conjunction with the Royal Air Force photographic experts.

On the first run from North to South, when the official timekeepers plotted Bluebird at an average speed of 297 miles an hour, the R.A.F. (who admit to a possible five mile an hour error in their calculations), suggest that Bluebird was doing 300 miles an hour.

New Brake
The R.A.F. say that peak speed was 320 miles an hour. But by the end of the measured kilometre, Campbell had decelerated to around 280 miles an hour before applying the hydraulic brake.

This brake was new to Bluebird, and was designed to create additional drag and also change the planing attitude of the boat for rapid deceleration.

The return run was made by Campbell immediately, without waiting to refuel. The reason for doing this was to beat his outgoing wake. Returning from South to North, the boat reached a peak of 328 miles an hour just entering the measured kilometre, then inexplicably dropped off to 300 miles an hour as it passed the first stake boat marking the beginning of the kilometre.

By the time it took off it was doing a bare 290 miles an hour - well below the first average speed of the first run.

So what went wrong?

Ken Norris, designer of the Bluebird, has been intimately associated with every detail of the R.A.F. analysis. He told me: "The take-off angle of Bluebird was calculated at six degrees at 300 miles an hour - a considerable angle of incidence for this type of speed-boat. A two-foot lift on the starboard sponson would give the equivalent at the centre of the boat of four degrees."

Pictures show that immediately before the take-off Bluebird's starboard sponson was just over 2ft out of the water. What caused the boat to lift the extra six inches which turned it into an aircraft?

Hit Branch?
After nearly a week of analysing every foot of film taken of the last fatal moments before Bluebird looped the loop and destroyed itself on the calm waters of Lake Coniston, the R.A.F. have decided that two things happened on the return run to cause disaster.

First: As Campbell accelerated towards the beginning of the measured kilometre he hit some object just below the surface of the water.

At the calculated 320 miles an hour speed, the boat was planning on just 18 square inches of metal in the water. Ken Norris showed me the starboard planing fin - a quarter-inch thick piece of steel, sharpened to a razor edge on its front end. In it are two large indentations which could only come from hitting a piece of floating wood such as a tree branch.

This collision forced the starboard sponson down into the water and then the sponsons natural buoyancy kicked it up into the air. From this point onwards the sponson remained airborne making Bluebird completely unstable.

Second: Then just 150 yards from the end of the timed kilometre, Campbell hit his own wash created in the original North to South run. This lifted the port sponson enough to raise the centre of the boat above the critical six degrees and the boat took off, looped the loop and smashed itself to pieces on the surface of the lake.

Analysis of the photographs has shown that a second before the boat became airborne, Campbell knew he was out of control and lifted his foot from the accelerator.

An R.A.F. observer told me: "You can see from the pictures that when Bluebird is almost vertical the rear end is perfectly mirrored in the water. If the full 5,500lb. thrust of the Orpheus engine had been switched on, the water beneath the tailpipe would have been ruffled by the pressure of the thrust."

Unsuspected
I asked Ken Norris if, in the last few moments, Campbell's life would have been saved by either a parachute brake or an ejector seat.

He said: "We tried the parachute brake at Ullswater about five years ago but the one and a half to two seconds required for it to become effective would have been too slow."

"An ejector seat would have to have been automatically operated once the boat passed its critical angle." So far as I know there is no automatic device which could cope with the vibrations created in Bluebird in any run over 230 miles an hour and yet have been sensitive enough to work at the very fine tolerance once the boat became unstable."

I believe, however, that Campbell thought he was well within the limits of the ultimate performance of the boat and at no time suspected that it was about to flip on to its back.

It was only a combination of two circumstances - either of which Bluebird and Campbell were capable of overcoming - which produced the fatal condition that finally destroyed the fastest boat the world has ever seen and killed her couragous driver.